Simplify _dl_find_symbol(). Currently, it returns three values:

 - the symbol it found, returned via the second argument
 - the base offset of the the object it was found in, via the return value
 - optionally: the object it was found in, returned via the last argument

Instead, return a struct with the symbol and object pointers and let the
caller get the base offset from the object's obj_base member.  On at least
aarch64, amd64, mips64, powerpc, and sparc64, a two word struct like this
is passed in registers.

ok mpi@, kettenis@

1 files changed, 33 insertions, 35 deletions

diff --git a/libexec/ld.so/sparc64/rtld_machine.c b/libexec/ld.so/sparc64/rtld_machine.c
index f106011606e..65ca082a7eb 100644
--- a/libexec/ld.so/sparc64/rtld_machine.c
+++ b/libexec/ld.so/sparc64/rtld_machine.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rtld_machine.c,v 1.63 2018/11/16 21:15:47 guenther Exp $ */
+/*	$OpenBSD: rtld_machine.c,v 1.64 2019/08/04 23:51:45 guenther Exp $ */
 
 /*
  * Copyright (c) 1999 Dale Rahn
@@ -251,9 +251,9 @@ _dl_md_reloc(elf_object_t *object, int rel, int relasz)
 		*where = relas->r_addend + loff;
 	}
 	for (; i < numrela; i++, relas++) {
-		Elf_Addr *where, value, ooff, mask;
+		Elf_Addr *where, value, mask;
 		Elf_Word type;
-		const Elf_Sym *sym, *this;
+		const Elf_Sym *sym;
 		const char *symn;
 
 		type = ELF_R_TYPE(relas->r_info);
@@ -281,14 +281,12 @@ _dl_md_reloc(elf_object_t *object, int rel, int relasz)
 			} else if (sym == prev_sym) {
 				value += prev_value;
 			} else {
-				this = NULL;
-				ooff = _dl_find_symbol_bysym(object,
-				    ELF_R_SYM(relas->r_info), &this,
-				    SYM_SEARCH_ALL|SYM_WARNNOTFOUND|
-				    ((type == R_TYPE(JMP_SLOT)) ?
-					SYM_PLT : SYM_NOTPLT),
-				    sym, NULL);
-				if (this == NULL) {
+				struct sym_res sr;
+
+				sr = _dl_find_symbol(symn,
+				    SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_NOTPLT,
+				    sym, object);
+				if (sr.sym == NULL) {
 resolve_failed:
 					if (ELF_ST_BIND(sym->st_info) !=
 					    STB_WEAK)
@@ -296,7 +294,8 @@ resolve_failed:
 					continue;
 				}
 				prev_sym = sym;
-				prev_value = (Elf_Addr)(ooff + this->st_value);
+				prev_value = (Elf_Addr)(sr.obj->obj_base +
+				    sr.sym->st_value);
 				value += prev_value;
 			}
 		}
@@ -304,18 +303,17 @@ resolve_failed:
 		if (type == R_TYPE(COPY)) {
 			void *dstaddr = where;
 			const void *srcaddr;
-			const Elf_Sym *dstsym = sym, *srcsym = NULL;
-			size_t size = dstsym->st_size;
-			Elf_Addr soff;
+			const Elf_Sym *dstsym = sym;
+			struct sym_res sr;
 
-			soff = _dl_find_symbol(symn, &srcsym,
+			sr = _dl_find_symbol(symn,
 			    SYM_SEARCH_OTHER|SYM_WARNNOTFOUND|SYM_NOTPLT,
-			    dstsym, object, NULL);
-			if (srcsym == NULL)
+			    dstsym, object);
+			if (sr.sym == NULL)
 				goto resolve_failed;
 
-			srcaddr = (void *)(soff + srcsym->st_value);
-			_dl_bcopy(srcaddr, dstaddr, size);
+			srcaddr = (void *)(sr.obj->obj_base + sr.sym->st_value);
+			_dl_bcopy(srcaddr, dstaddr, dstsym->st_size);
 			continue;
 		}
 
@@ -591,10 +589,10 @@ _dl_bind(elf_object_t *object, int index)
 {
 	Elf_RelA *rela;
 	Elf_Word *addr;
-	Elf_Addr ooff, newvalue;
-	const Elf_Sym *sym, *this;
+	Elf_Addr newvalue;
+	struct sym_res sr;
+	const Elf_Sym *sym;
 	const char *symn;
-	const elf_object_t *sobj;
 	int64_t cookie = pcookie;
 	struct {
 		struct __kbind param[2];
@@ -632,15 +630,14 @@ _dl_bind(elf_object_t *object, int index)
 	sym += ELF64_R_SYM(rela->r_info);
 	symn = object->dyn.strtab + sym->st_name;
 
-	this = NULL;
-	ooff = _dl_find_symbol(symn, &this,
-	    SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_PLT, sym, object, &sobj);
-	if (this == NULL)
+	sr = _dl_find_symbol(symn, SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_PLT,
+	    sym, object);
+	if (sr.sym == NULL)
 		_dl_die("lazy binding failed!");
 
-	newvalue = ooff + this->st_value;
+	newvalue = sr.obj->obj_base + sr.sym->st_value;
 
-	if (__predict_false(sobj->traced) && _dl_trace_plt(sobj, symn))
+	if (__predict_false(sr.obj->traced) && _dl_trace_plt(sr.obj, symn))
 		return (newvalue);
 
 	/*
@@ -790,24 +787,25 @@ _dl_md_reloc_all_plt(elf_object_t *object)
 	for (i = 0; i < numrela; i++, relas++) {
 		Elf_Addr value;
 		Elf_Word *where;
-		const Elf_Sym *sym, *this;
+		struct sym_res sr;
+		const Elf_Sym *sym;
 
 		if (ELF_R_TYPE(relas->r_info) != R_TYPE(JMP_SLOT))
 			continue;
 
 		sym = object->dyn.symtab + ELF_R_SYM(relas->r_info);
 
-		this = NULL;
-		value = _dl_find_symbol_bysym(object, ELF_R_SYM(relas->r_info),
-		    &this, SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_PLT, sym, NULL);
-		if (this == NULL) {
+		sr = _dl_find_symbol(object->dyn.strtab + sym->st_name,
+		    SYM_SEARCH_ALL|SYM_WARNNOTFOUND|SYM_PLT,
+		    sym, object);
+		if (sr.sym == NULL) {
 			if (ELF_ST_BIND(sym->st_info) != STB_WEAK)
 				fails++;
 			continue;
 		}
 
 		where = (Elf_Word *)(relas->r_offset + loff);
-		value += this->st_value;
+		value = sr.obj->obj_base + sr.sym->st_value;
 
 		if (__predict_false(relas->r_addend)) {
 			/*